|Quoting einsteinboricua (Reply 5):|
IMO, it's pointless. What are the benefits of leaving my seat upright during takeoff or landing?
It is all about the speed of evacuating a plane. Seats upright make it easier to evacuate and the airplane was certified with that criteria. On some of the newer business class and first class seats where recline does not affect the row behind, a reclined position is often allowed.
Also, seats must be able to withstand either 9G or 16G (depending on cert requirements). The seats are designed to meet these requirements in the upright position. They are tested accordingly. Some business class seats allow recline, but they have to meet the safety requirements. Some such as the BA
seats have a locked position which is partially reclined for takeoff and landing. This is where the seat meets the acceleration force requirements.
There is a lot of engineering that goes behind the certification of aircraft that is not visible to the unaware passenger. The strict requirements are why more crashes are survivable. If it is in the FARs, there is a reason for it. Requirements on an airplane are not there just to inconvenience passengers.
With that said, some countries and airlines do not strictly enforce the requirements like in the US. Some Middle Eastern, African & Asian airlines are notorious for this. It is up to the regulatory bodies to ensure compliance. Some regulatory bodies are so weak in enforcing requirements that their airlines are banned or restricted from operating in the EU and/or US.
If you have never designed an airplane part before, let the real designers do the work!